Also known as Pluto, or Aides, Pluto was the dark, grim god of the underworld, and ruled supreme there. He was a son of Rhea, and like his brothers Zeus and Poseidon, demanded a share of the Earth following the overthrow of Kronos. The three siblings cast lots, and to Hades fell the world below. His domain was a bleak one:the three rivers running along its environs were named Styx, Acheron (the river of eternal woe), Pyriplegethon (the stream of fire), Kokytos (the river of weeping and wailing) and Lethe (the river of forgetfulness). Once someone had passed over into the realm of Hades, there was no return (except in the case of Orpheus. Charon, the aged boatman of the dead, ferried the souls of the departed across the river Styx, which flowed into Hades, and once there they were received by Hades and his wife, Persephone.
The lord of the dead had carried off Persephone from the world above, smitten with her beauty and deaf to the cries of her mother, Demeter. Indeed, when Demeter finally found her daughter, Persephone explained that she had eaten of a pomegranate that Hades had given her, and could never return to the upper world. The entrance to Hades was guarded by the triple-headed dog Cerberus, and for those who had led reasonably righteous lives, the afterlife in the underworld was a sort of shadow of their former life, where they could continue to perform the labours and carry on the occupations they had occupied in life. Occasionally, a shade might be allowed to return temporarily to the world above, as a ghost, to their friends, or even summoned by the sacrifice of blood which, when drank by the shade, restored to them partial speech and consciousness, so that they could discourse with the living.
But for those who had led wicked lives or lives the gods did not agree with there was the realm of Tartaros, where all the sins and evils the departed had practiced in the world above were punished, usually in a manner symbolic of their crime. Cases in point here were Tantalos, Ixion, Sisyphos, Tityos and the Danaides, all of whom can be found under their own separate entries, so we will not go into their punishment here.
There also existed in Tartaros Elysion, where the happy and the blessed were received, and which approximates as closely to the Christian ideal of Heaven as is possible, showing that Hades, though dark and forbidding, was not all doom and gloom, punishment and revenge. Hades and Persephone were also seen to be judges of the dead, and in this capacity they were assisted by three heroes whose earthly deeds had identified them as great in wisdom and justice. They were called Minos, Rhadamanthys and Aeakos, the last also being the gatekeeper of the lower region of Hades.